Ajax Harwood Clinic

Folate (serum and RBC folate)

This test is useful only in specific situations — it's not right for everyone who asks about it.

What this test is

Folate is a B vitamin. Your body needs it to make healthy red blood cells. In Canada, flour and pasta have added folic acid since 1998. Because of this, true folate deficiency is now rare. Testing makes the most sense in two cases. One is when a blood count shows a certain type of anemia. The other is a gut problem that affects how you absorb nutrients. A related test, RBC folate, is used in similar cases. For most people with plain tiredness, this test will not find anything. It is not routinely recommended for that alone.

Want to see the full clinical reasoning? The reference we use for this test is open to anyone — it is detailed and written for clinicians, and you are welcome to read it.

Open the clinician reference →

Looking for other tests, or more on a condition an ND raised? Explore ask.ajaxharwoodclinic.com →

General health information for Ajax Harwood Clinic patients and the public — not medical advice, and not a substitute for seeing your own doctor. Last reviewed 2026-09-23.